1. Field of the Invention
The present invention relates to a non-magnetic substrate for a magnetic head having on its main surface various components constituting a magnetic head. Moreover, the present invention relates to a magnetic head having various components for recording and/or reproducing.
2. Description of Prior art
A magnetic head is mounted on a magnetic recording/reproducing apparatus for recording and/or reproducing of an information signal onto/from a magnetic recording medium (hereinafter, referred to as recording/reproducing). Such a magnetic recording/reproducing apparatus may be, for example, a video tape recorder (VTR) and a digital audio tape (DAT) having a magnetic head on a drum rotating at a high speed wherein a tape-shaped magnetic recording medium slides along the drum, so that recording/reproducing is performed by the so-called helical scan method. Moreover, a hard disc drive (HDD) and a floppy disc drive (FDD) are used for performing recording/reproducing by a magnetic head for a disc-shaped magnetic recording medium such as a magnetic disc and a magneto-optical disc.
A magnetic head is normally constituted by a coil wound around a magnetic core made from a magnetic material having a high permeability. Such a magnetic head is called electromagnetic inductive type magnetic head because recording/reproducing is performed to/from a magnetic recording medium using electromagnetic inductance between a magnetic core and a coil.
A conventional magnetic head has a magnetic core constituted by two magnetic core half bodies made by machining a bulk magnetic material which are combined via a magnetic gap. Recently, however, a higher magnetic density of a magnetic signal is required and it is necessary to accurately record/reproduce a small magnetic signal. However, conventional magnetic head in which a magnetic core is formed by machining a bulk material cannot obtain a sufficiently narrow track and a sufficiently narrow gap.
To cope with this, a magnetic head for a high recording density has been suggested and used in practice such as a layered type magnetic head, thin film type magnetic head, a magnetoresistive head (MR head).
The layered magnetic head is prepared as follows. A metal magnetic layer is sandwiched by a non-magnetic substrate as a guard material, thus obtaining a magnetic core half body. A pair of magnetic core half bodies are attached to each other by glass melting or the like. In the layered type magnetic head, a pair of magnetic core half bodies are connected via a glass, so that the metal magnetic layer serves as a magnetic core.
In the thin film type magnetic head, various head elements such as a magnetic core and a magnetic coil are formed on a non-magnetic substrate by various thin film processing techniques such as dry etching. The thin film type magnetic head in which various head members are formed by the thin film processing technique has an advantage that a highly accurate magnetic head can be produced in a large quantity.
The MR head has a magnetoresistive element (MR element) formed on a non-magnetic substrate and is dedicated for reproducing. The MR head which does not require a magnetic coil can be produced in a small size and has a high sensitivity. Accordingly, the MR head attracts attention as a magnetic head for high recording density.
In the aforementioned various magnetic heads, the non-magnetic substrate is made from MnOxe2x80x94NiO, Al2O3xe2x80x94TiC, or the like.
The aforementioned MnOxe2x80x94NiO system material and Al2O3xe2x80x94TiC system material have a wear resistance smaller than a ferrite single crystal, for example. Accordingly, a magnetic head having a non-magnetic substrate formed from such a material has a greater wear by the sliding of the magnetic recording medium, compared to a ferrite magnetic head and a MIG (metal in gap) magnetic head having a magnetic core formed from a ferrite single crystal. That is, there is a problem that the service life as a magnetic head is very short. The wear is especially remarkable when used at a low temperature with a high humidity.
Moreover, in a case of the MR head, if the non-magnetic substrate is worn away, the bias state and the resistance of the MR element are greatly deviated from the initial state, deteriorating the reproducing output and the output waveform. When the MR head is used as a floating type magnetic head wherein a magnetic recording medium does not slide, there is no problem of wear of the non-magnetic substrate. However, when the MR head is used in a video tape recorder for helical scan type reproducing, the non-magnetic substrate has a problem of wear and it is difficult to obtain a stable high accuracy in reproducing operation.
Furthermore, a magnetic head having a non-magnetic substrate formed from the aforementioned MnOxe2x80x94NiO or Al2O3xe2x80x94TiC, has a problem during a production procedure that a grindstone is easily worn out when grinding the sliding surface of the magnetic recording medium. That is, such a magnetic head. requires frequent replacement of the grindstone.
It is therefore an object of the invention to provide a non-magnetic substrate for a magnetic head having an excellent wear resistance and excellent property for machining. Another object of the present invention is to provide a magnetic head having a non-magnetic substrate having an excellent wear resistance and excellent property for machining.
The non-magnetic substrate for a magnetic head according to the present invention is formed by a non-magnetic material containing TiO2 as a main content.
The non-magnetic substrate for a magnetic head having the aforementioned configuration has a sufficiently excellent wear resistance.
Moreover, the non-magnetic substrate for a magnetic head according to the present invention is formed by a non-magnetic material containing TiO2 and NiO as main contents wherein a content of TiO2 is equal to or above 70 mol % and below 100 mol %.
The non-magnetic substrate for a magnetic head having the aforementioned configuration has a sufficiently excellent wear resistance and machining characteristic.
Furthermore, the magnetic head according to the present invention includes a non-magnetic substrate on which components for performing recording and/or reproducing are arranged, the non-magnetic substrate is formed by a non-magnetic material containing TiO2 as a main content.
The magnetic head having the aforementioned configuration has a sufficiently excellent wear resistance and suppresses wear by sliding of a magnetic recording medium.
Moreover, the magnetic head according to the present invention includes a non-magnetic substrate on which components for performing recording and/or reproducing are arranged. The non-magnetic substrate is formed by a non-magnetic material containing TiO2 and NiO as main contents wherein a content of TiO2 is equal to or above 70 mol % and below 100 mol %.
The magnetic head having the aforementioned configuration has a sufficiently excellent wear resistance and suppresses wear by sliding of a magnetic recording medium. Moreover, the magnetic head has a sufficiently excellent machining characteristic and can reduce the time required for grinding, thus contributing to improvement of productivity.